Shopify

Web performance consultant for Shopify

Optimize web performance on Shopify stores

Shopify is SaaS: no server access, no backend tuning. Optimization happens on theme, apps and third-party scripts. I audit every app by its real impact, rebuild the theme when needed, and prioritize LCP for green Core Web Vitals.

100% satisfied clients Data 2023-2026 • 8+ years XP • 35+ clients partnered
View my client cases

They trust me

CHANEL
DIOR
Decathlon
April Moto
SiriusXM
Make Up Forever
Camif
RIMOWA
Jimmy Fairly
Wecasa
Chronovet
CHANEL
DIOR
Decathlon
April Moto
SiriusXM
Make Up Forever
Camif
RIMOWA
Jimmy Fairly
Wecasa
Chronovet

Shopify symptoms calling for an audit

Shopify hides the backend but spotlights the consequences of a heavy theme and an uncontrolled apps pileup.

📱 Red mobile INP on product page or checkout

Shopify delivers red INP as soon as you exceed 4-5 active JavaScript-injecting apps. Main thread saturates, every interaction feels sluggish. Apps audit + aggressive deferral fixes it.

🐌 LCP at 4 seconds and above on mobile

Hero image not prioritized, JPEG format instead of WebP/AVIF, lazy loading misplaced on the LCP image. Shopify Image API supports next-gen formats but the theme must use them.

📦 Additional JS bundle above 1 MB

Klaviyo + Loox + Recart + Loyalty + chat + analytics: each app adds its script. With a commercial theme like Booster or Avada Shopify, JS weight easily exceeds 2 MB. Apps audit + selective removal gains 50% weight.

🎨 Pre-Online Store 2.0 obsolete theme

Brooklyn, Debut, Minimal themes date from 2017-2018, don't use JSON sections, and are architecturally obsolete. Moving to a lean OS 2.0 theme gains 30 to 50% on overall weight.

🛒 Customized Shopify Plus checkout killing INP

On Shopify Plus, the checkout is customizable. Poorly coded customizations (heavy JS validations, injected third-party scripts) degrade INP. Chrome DevTools profiling identifies Long Tasks for refactoring.

🔁 Useful app installed but loaded everywhere

A review app (Loox, Judge.me) is useful on the product page, useless on home or cart. Conditional loading via Liquid fixes it while keeping the app active where it serves.

Shopify optimization methodology

4 steps to transform your performance

1
Step 1

1. Apps audit + impact measurement

List active apps, measure JS weight and LCP/INP impact per app via SpeedCurve LUX or equivalent. Identify apps to remove, defer, or replace.

2
Step 2

2. Current theme evaluation

Audit the theme (OS 2.0 or pre-2.0 architecture, asset weight, Liquid quality). Evaluate rebuild vs in-place optimization.

3
Step 3

3. Liquid and asset optimization

LCP image prioritization (fetchpriority, next-gen formats via Shopify Image API), defer non-critical scripts, proper lazy loading, critical section optimization.

4
Step 4

4. Continuous monitoring

Install SpeedCurve LUX or use the Shopify Web Performance dashboard. Track Core Web Vitals over time to block regressions tied to future app additions.

Mission commitments

-50% total JavaScript weight
-1.5s typical mobile LCP gained
INP stabilized under 200ms
Continuous apps and theme monitored
FAQ

Frequently asked questions

Can you really optimize Shopify without server access?
Yes, and significantly. The Shopify backend is already highly optimized (global CDN, TTFB < 200ms). Levers concentrate on theme, apps, third-party scripts and proper use of Shopify features (Image API, sections, metafields). 80% of Shopify webperf gains come from these theme-side levers.
Do you need to move to Shopify Plus to optimize?
Not necessarily. Shopify Plus brings customizable checkout, Shopify scripts, multi-store. Performance-wise, levers are the same as standard Shopify. Plus is useful for business constraints (B2B, branded checkout, volume) more than for pure performance.
Should you move to an Online Store 2.0 theme?
For sites still on pre-2017 themes, yes. JSON sections, native metafields and OS 2.0's modern architecture ease optimization and reduce weight. For 2019-2020 themes already OS 2.0-compatible, in-place optimization usually suffices.
How are your Shopify engagements structured?
My Shopify engagements run as continuous follow-up. Initial apps and theme audit, then regular optimization sprints (Liquid refactor, audit of new apps installed, LCP priority adjustment). A Shopify merchant never stops adding apps or marketing scripts — continuous engagement protects performance over time.

Get your Shopify green

Apps audit with impact measurement
Liquid + theme optimization
LCP prioritization + script deferral
100% satisfied clients
Data 2023-2026
Testimonials

What my clients say

Excellent work.
Paul has significantly improved the site's speed and perfectly aligned it with Google's recommendations.
Professional, thorough, and efficient, I highly recommend.

Nicolas - April Moto

Digital & E-commerce Director

We are very satisfied with Paul's work. He is quick, available, and particularly effective. Since his arrival, very good results have been observed, both in terms of performance and responsiveness. A real asset for our team.

Léo - Luxury brand

E-commerce Product Owner

I don't know if we've said it enough.
But if you want to improve your loading speed,
Make Google happy and get your Core Web Vitals in the green,
Contact Paul Delcloy.

Florian Darroman - Les Makers

Co-founder

Shopify, SaaS constraints and concentrated levers

Shopify is a SaaS platform: no server access, no Varnish or Redis tuning, no custom installs. That's also its commercial strength (zero infrastructure to manage), and why Shopify powers hundreds of thousands of stores. Web performance-wise, the lack of server access shifts the whole stake onto what you control: the Liquid theme, installed apps, third-party scripts and proper use of native Shopify features (Online Store 2.0, integrated CDN, image API).

Shopify still gives an excellent starting point: included global CDN, automatically scaled hosting, origin TTFB generally below 200ms. The problem starts when you pile up a heavy theme + 15 apps + 6 marketing scripts. Core Web Vitals drift, mobile INP turns red, catalog SEO drops.

Apps audit, lever number one

On a Shopify mission, the first work-stream is almost always the apps audit. Klaviyo, Loox, Judge.me, ReCharge, Loyalty Lion, Recart, PageFly: each app typically adds 50 KB to 300 KB of JavaScript, often loaded on every page (not just where it's useful). With 15 apps, you easily exceed 2 MB of additional JS.

The audit measures each app's impact on LCP, INP and CLS via SpeedCurve LUX or an equivalent RUM. Some apps can be uninstalled (rarely used by visitors), others deferred (loaded only on certain pages), others replaced by lighter custom integration. Five to ten optimized apps typically gain 1.5 seconds of LCP.

Online Store 2.0 and lean theme

Shopify released Online Store 2.0 in 2021: new theme architecture, JSON sections, native metafields support. Pre-2.0 themes (Brooklyn, Debut, Minimal) are obsolete and heavy. Moving to a lean Online Store 2.0 theme (Dawn, Sense, or a lightweight custom theme) is often the second work-stream after apps audit.

The final angle is Liquid optimization: inefficient loop elimination, proper section_render usage, lazy loading of non-LCP images, fetchpriority on the hero image. For stores wanting a complete e-commerce audit, these levers fit into a broader effort.

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